Data will be measured from crystals of Zn-alpha2-glycoprotein (ZAG), invasin, and the neonatal Fc receptor (FcRn). ZAG is related to class I MHC molecules and has been suggested to play a role in breast cancer. We have solved the structure to 2.9 E using x-rays generated from an in-house rotating anode, and intend to collect high resolution data from cryopreserved crystals in order to interpret electron density that appears to represent a small molecule ligand bound to ZAG. Invasin is 120 kDa protein present on the outer membrane of the enteropathogenic bacterium Yersinia pseudotuberculosis. Invasin binds to several b1 integrins and this interaction mediates the penetration of the bacteria into the host cell. Crystals of an invasin fragment have been grown and a preliminary 2.2 E crystal structure has been solved. FcRn mediates the transport of IgG from the mother to the developing fetus and protects IgG from protein catabolism. We have determined the structure of human FcRn to 2.5 E resolution using data collected at SSRL.